Module 1: DNA and Gene Structure

Question 1

What is DNA and what is its function?

Answer 1

• DNA contains genes which have 2 roles in the cell
  -genes are the uni of biological info
  -genes are units of inheritance
• DNA holds the instructions for an organisms development, survival and reproduction

Question 2

What is the structure of DNA?

Answer 2

• stable
• DNA is a polymer - the monomers are called nucleotides

Question 3

What are the components of a nucleotide?

Answer 3

Has 3 parts:
1. sugar = 2’ deoxyribose
2. phosphate groups (alpha, beta and gamma)
3. base

Question 4

How many bases are in DNA?

Answer 4

4

Question 5

How are bases attached to the sugar?

Answer 5

with a β-N-glycosidic bond (beta-N)

Question 6

Which bases are purines?

Answer 6

Adenine and Guanine
(A and G)

Question 7

Which bases are pyrimidines?

Answer 7

Cytosine and Thymine
(C and T)

Question 8

What is Chargaff’s Rule?

Answer 8

Total no. of purines in a DNA molecule = total no. of pyrimidines

Question 9

What are the official names of the four nucleotides?

Answer 9

• 2’ -deoxyadenosine 5’ -triphosphae dATP A
• 2’ -deoxyguanosine 5’ -triphosphate dGTP G
• 2’ -deoxycytidine 5’ -triphosphate dCTP C
• 2’ -deoxythymidine 5’ -triphosphate dTTP T